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<?php |
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declare (strict_types=1); |
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namespace Np\linAlgb\decompositions; |
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use Np\matrix; |
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use Np\vector; |
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use Np\core\lapack; |
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use Np\exceptions\invalidArgumentException; |
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/** |
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* Eigen |
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* |
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* The Eigen decompositon or (Spectral decomposition) is a matrix factorization resulting in a matrix of eigenvectors and a |
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* corresponding array of eigenvalues. |
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* |
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* @package Np |
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* @category Scientific Library |
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* @author ghost (Shubham Chaudhary) |
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* @email [email protected] |
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* @copyright (c) 2020-2021, Shubham Chaudhary |
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*/ |
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class eigen { |
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protected $eignVal; |
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protected $eignVec; |
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public static function factory(\Np\matrix $m, bool $symmetric = false): self { |
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if (!$m->isSquare()) { |
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throw new invalidArgumentException('A Non Square Matrix is given!'); |
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} |
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$wr = vector::factory($m->col); |
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$ar = $m->copy(); |
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if ($symmetric) { |
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$lp = lapack::syev($ar, $wr); |
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if ($lp != 0) { |
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return null; |
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} |
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return new self($wr, $ar); |
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} else { |
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$wi = vector::factory($m->col); |
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$vr = matrix::factory($m->col, $m->col); |
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$lp = lapack::geev($ar, $wr, $wi, $vr); |
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if ($lp != 0) { |
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return null; |
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} |
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return new self($wr, $vr); |
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} |
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} |
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/** |
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* |
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* @param vector $eignVal |
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* @param matrix $eignVec |
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*/ |
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protected function __construct(vector $eignVal, matrix $eignVec) { |
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$this->eignVal = $eignVal; |
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$this->eignVec = $eignVec; |
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} |
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/** |
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* Return the eigenvalues of the eigen decomposition. |
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* |
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* @return vector |
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*/ |
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public function eigenVal(): vector { |
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return $this->eignVal; |
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} |
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/** |
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* Return the eigen vectors of the eigen decomposition. |
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* |
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* @return matrix |
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*/ |
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public function eigenVec(): matrix { |
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return $this->eignVec->transpose(); |
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} |
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} |
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